tun: return proper error code from tun_do_read
Instead of -1 with EAGAIN, read on a O_NONBLOCK tun fd will return 0. This
fixes this by properly returning the error code from __skb_recv_datagram.
Signed-off-by: Alex Gartrell <agartrell@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index df5e948..c0df872 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1380,7 +1380,7 @@
skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
&peeked, &off, &err);
if (!skb)
- return 0;
+ return err;
ret = tun_put_user(tun, tfile, skb, to);
if (unlikely(ret < 0))